Querying Databases with Machine Learning Model References

3. The system of claim 1, wherein the database engine is implemented as part of a database service of a provider network, wherein the machine learning model is hosted as part of a machine learning service of the provider network, and wherein to cause the evaluation of the machine learning model, the program instructions when executed by the at least one processor cause the at least one processor to perform the method to at least, send a request from the database engine hosted in the database service to a machine learning model host in the machine learning service to perform an evaluation of the one or more machine learning models.

8. The method of claim 4, further comprising selecting an operation to cause the one or more machine learning models to provide information for a plurality of data values as part of generating a plan to perform the database query.

9. The method of claim 4, further comprising returning a result for the database query that includes the information provided by the one or more machine learning models.

10. The method of claim 4, further comprising generating a query plan to perform the database query that includes a first operation to obtain the data from the database and a second operation to request the evaluation of the one or more machine learning models.

12. The non-transitory, computer-readable storage medium of claim 11, wherein the program instructions when executed by the one or more computing devices cause the one or more computing devices to further implement selecting an operation to cause the one or more machine learning models to perform an evaluation for a single data value as part of generating a plan to perform the database query.

14. The non-transitory, computer-readable storage medium of claim 13, wherein the request to generate the one or more machine learning models specifies the one or more machine learning techniques to apply.

15. The non-transitory, computer-readable storage medium of claim 11, wherein the database is hosted as part of a database service of a provider network, and wherein the one or more machine learning models are hosted as part of a machine learning service of the provider network.